Dual outlet exhaust system

ABSTRACT

An exhaust system for internal combustion engines comprises flow balanced dual outlet conduits.

Morrish [81/36 D O Unlted States Patent 11 1 1111 3,739,873 Shaughnessy1 June 19, 1973 DUAL OUTLET EXHAUST SYSTEM 2,940,249 6 1960 Gospodar 18136 D 2,991,160 7 1961 Claussen 181/45 [75] Invent Jame? Pleasant3,166,150 1/1965 Phelps 181/60 Lake, M1ch. 3,317,001 5 1967 Powers 61 al181/36 13 Assigneez n a ine, VCEZIB [22] Filed: t 3 1971 FOREIGN PATENTSOR APPLICATIONS 1 428,695 5/1926 Germany 181/36 D 1 PP 177,773 647,118 61937 Germany 1,035,973 8/1958 Germany r 481,480 3/1938 Great Britain....

fag 3%: 923,492 4/1963 Great Britain 181/60 [58] Field 0 Search IIIIIII81/36 R36 B 35 C, 641,878 7 1962 Italy 181 60 ll 5 60 5 5 PrzmaryExammer-R1chard B. W1lk1nson Assistant ExaminerJohn F. Gonzales [56]References Cited Attorney-J. Kmg Harness, Paul F. S1eb0ld, Cyrus UNITEDSTATES PATENTS G. Minkler et aL 2,881,851 1 4 1959 Willsea 181 401,949,667 3/1934 Transiskus 181/44 57 B A T 2,047,443 7/1936-Starkweather et al 181/44 2,297,046 9/1942 Boume 181/35 B F system forengmes 2,305,946 12/1942 Wilson et al. 181/35 13 compflses flow balanceddual Outlet condults- 2,888,001 5 1959 8 Claims, 5 Drawing Figures withdual exhaust manifolds 3 .tively, flow is combined in a single exhaustpipe section BRIEF SUMMARY OF THE INVENTION It is the purpose of theinvention to provide a highly effective, minimum cost exhaust gassilencing system for internal combustion engines.

' The invention accomplishes this object by means of a system that has asingle muffler that discharges into two flow balanced branches thatconvey the gas to the system outlet points.

' DESCRIPTION or THE DRAWINGS FIG. 1 is a perspective, schematic view ofan exhaust system embodying the invention;

FIG. 2, is an enlarged 'view of a portion of the system of FIG. 1,broken away to Show a modification;

FIG. 3 is an enlarged cross section through one of the outlet sectionsshowing-a means for forming a flow balancing restriction therein;

FIG. 4 is a view similar to FIG. 1 showing another embodiment of theinvention; and

FIG. 5 is a view similar to FIG. 1 other embodiment of the invention.

DESCRIPTION OF THE INVENTION The internal combustion engine 1 typifies ahigh powered V-8 unit used in many modern automobilesand'5. The exhaustsystem 7 comprises dual, uniform diameter exhaust pipes 9 and 11connected to the manifolds 3 and 5, respecand joined together in a Ypoint 13 so that their and 4 showing anthat leads to the inlet 17 of asingle exhaust gas muffler 19. After silencing in the muffler 19 gasesleaving the, muffler outlet 21 enter a single tailpipe section 23 thatisconnected thereto. A short distance. from the outlet 21, the uniformdiameter tailpipe member 25 that provides section 23 has an openingformed in its wall and a branch uniform diameter tailpipe member 27 iswelded tomember 25, around the opening in a Y joint 29 so that thesystem7' has a dual tailpipe structure, i.e., branch tailpipe 27 and thesection" 31 of tailpipe member 25 which is downstream from the Y joint29.

In the system illustrated the muffler 19 is located substantially to theright of the center line of the vehicle so that in order that therespective outlets 33 and 35 of the sections 2'7 and 31'be symmetricallylocated at the rear of the vehicle on opposite sides of the center line,the section 27 has a portion 37 that diverges from the tailpipemember25. The sections 27, and31 have transversely aligned kick-upsections or'arches 39 and 4-1,. respectively, to go overthe rear axle ofthe vehicle and these merge intoend sections 43 and 45,. respectively,that terminate in the outlets 33 and 35. 7

It isYdesired that the flow through the dualv tailpipe sections 27 and3lbebalanced or equalized'and appropriate means is. employed, wherenecessary, to achieve. this balance. In the structure illustrated, thesection 31 is somewhat shorter in length than section 27 and also inline with flow'from the muffler outlet 21 and, hence, in the absence offlow balancing means would presentless resistance to flow than thebranch 27. Asa balancingmeans, therefore, the branchv 27 may be largerin cross section or diameter than the section 31. Alternatively, asshown in FIG. 2, the section 31 may contain a fixed restrictor ororificev means 47 in the formofa Z-shaped tubular insert tosubstantially equalize its resistance with that of the section 27. Afurther alternative is shown in FIG. 3 where pinch sections 48 are usedto reduce the inner diameter of section 31.

The operation of the system 7 is apparent. The system has the advantageof presenting the appearance of a dual exhaust system since the singlesystem components are located beneath the automobile and out of sight.The use of a single muffler instead of two mufflers causes the mufflerto operate at higher temperature level than the mufflers of a true dualsystem and this promotes a longer muffler life.

An important advantage of the dual outlet arrangement of the inventionis its reduction in the sound level of gas leaving the muffler 19. Thecombined areas of branches 27 and 31 substantially exceeds the area ofmuffler outlet 21 and that of the upstream gas passages includingsection 23 and the gas velocity is therefore substantially reduced inthe dual tailpipe portion of the System. This diminishes the air rusheffect and the noise associated with it and thereby lowers the soundlevel at the rear of the system 7.

While it is preferred that a single inlet muffler, as illustrated, beused in systems of the invention, it'is apparent that benefits of theinvention are also obtained if the muffler is ofa dual inlet, singleoutlet type in which case the exhaust pipes 9 and 11 would not merge butwould feed directly into two muffler inlets. Further, as seen in FIG. 4,the muffler'may have a single inlet and this together with smalldiameter of pipes inside the muffler may result in a high gas velocityand the possibility of air rush noise which the balanced dual tailpipearrangement of FIG. 4 overcomes.

In FIG. 4, the engine 101 has only a single exhaust manifold 103discharging into a single exhaust pipe 105 that leads to the inlet 107of muffler 109. The muffler 109 has a single outlet 111 emptying into atailpipe member 113 (similar to member 25) that includes a uniformdiameter inlet section 115 connected to the outletlll. The member 113has a tailpipe section 117 that is substantially in line with outlet 111and a hole in its sidewall is covered to form a Y joint 119 by branchtailpipe section 121 which is welded to it. As in the case of member 25the section 117 (like section 31) presents less resistance to flow andflow balancing means in the form of a reduced diameter portion 123 ofpipe section 117 is provided to substantially equalize the resistance ofthe two sides 117 and 121.

In FIG. 5, a dual manifold engine 201 discharges exhaust gases intoexhaust pipes 203 and 205 which are connected together in a Y joint 207to form a single exhaust pipe section 209 that is connected to the inletbushing 211 of muffler 213. The muffler is of the dual outlet type withoutlets 215 and 217 connected to two tailpipes 219 and 221 of unequallength. Suitable flow balancing means are incorporated in one or both ofthe pipes to equalize flow and resistance, this being illustrated asorifice members 223 and 225, respectively, in pipes 219 and 221.

Thus, it is apparent that the invention may be used with any internalcombustion engine to reduce exhaust noise of various types and that itis particularly useful in systems wherein there is a muffler having asingle inlet bushing. Modifications in the specific'details illustratedmay be made without departing from the spirit and scope of theinvention.

I claim:

1. An exhaust system for internal combustion engines comprising a singlemuffler having outlet means, a single tailpipe section connected to andreceiving all gas from said outlet means, and a pair of tailpipesections connected to and receiving all gas from said single tailpipesection, the combined cross sectional area of the pair of sections beinggreater than the cross sectional area of the single tailpipe section,and means for substantially equalizing flow in the pair of tailpipesections, said means comprising a reduced diameter cross section in oneof the pair of tailpipe sections acting as a flow restricting orifice.

2. An exhaust system for internal combustion engines comprising a singlemuffler having outlet means, a single tailpipe section connected to andreceiving all gas from said outlet means, and a pair of tailpipesections connected to and receiving all gas from said single tailpipesection, the combined cross sectional area of the pair of sections beinggreater than the cross sectional area of the single tailpipe section,and means for substantially equalizing flow in the pair of tailpipesections, one of said pair of tailpipe sections being larger in crosssection than the other and the difference in cross section between twosections comprising said means.

3. A dual type exhaust system for an internal combustion engine havingtwo exhaust manifolds comprising a pair of exhaust pipes connected oneto each of said manifolds, a single muffler, means connecting bothexhaust pipes to said muffler, said muffler having a single outlet, asingle tailpipe section connected to and receiving all gas from saidoutlet, a pair of tailpipe sections connected to and receiving all gasfrom said single tailpipe section, the combined cross sectional area ofthe pair of sections being greater than the cross sectional area of thesingle tailpipe section and the flow through the respective sections ofsaid pair being substantially equal, said muffler having a single inletand said means comprising a common exhaust pipe connected to andreceiving gas from both said exhaust pipes and connected to said singleinlet.

4. In an exhaust system for an internal combustion engine, a singlemuffler having inlet means and outlet means, exhaust pipe meansconnecting the engine to the inlet means, tailpipe means connected toand receiving all gas from said outlet means, said tailpipe meansincluding a pair of tailpipe sections connected to and receiving all gasfrom said muffler, and means for substantially equalizing flow in thepair of tailpipesections, said outlet means comprising two separateoutlets connected respectively to said tailpipe sections, at least oneof said tailpipe sections including flow restricting means to serve assaid flow equalizing means.

5. An exhaust system for internal combustion engines comprising a singlemuffler having outlet means, a single tailpipe section connected to andreceiving all gas from said outlet means, and a pair of tailpipesections connected to and receiving all gas from said single tailpipesection, the combined cross sectional area of the pair of sections beinggreater than the cross sectional area of the single tailpipe section,one of said tailpipe sections being substantially longer than the other,and means for substantially equalizing flow in the pair of tailpipesections.

6. A dual type exhaust system for an internal combustion enginehavingtwo exhaust manifolds comprising a pair of exhaust pipes connected oneto each of said manifolds, a single muffler, means connecting bothexhaust pipes to said muffler,.said muffler havinga single outlet, asingle tailpipe section connected to and receiving all gas from saidoutlet, a pair of tailpipe sect'ions connected to and receiving all gasfrom said single tailpipe section, one of said pair of tailpipe sectionsbeing substantially longer than the other, the combined cross sectionalarea of said pair of tailpipe sections being greater than the crosssectional area of the single tailpipe section, and flow restrictionmeans in one of the tailpipe sections whereby the flow through therespective sections of said pair are substantially equal.

7. A dual type exhaust system comprising a single rectangular mufflerhaving a single tubular inlet at one end and a single tubular outlet atthe other end, a single exhaust pipe connected to said inlet and asingle tailpipe connected to said outlet, a pair of exhaust pipesconnected in a Y joint to said single exhaust pipe, and a pair oftailpipes connected in a Y joint to said single tailpipe, the combinedareas of said pair of tailpipes being larger than the area of saidsingle tailpipe.

8. In an exhaust system for an internal combustion engine, a singlemuffler having inlet means and outlet means, exhaust pipe meansconnecting the engine to the inlet means, tailpipe means connected toand receiving all gas from said outlet means, said tailpipe meansincluding a pair of tailpipe sections connected to and receiving all gasfrom said muffler, and restriction means in one of the tailpipe sectionsfor substantially equalizing flow in the pair of tailpipe sections.

1. An exhaust system for internal combustion engines comprising a singlemuffler having outlet means, a single tailpipe section connected to andreceiving all gas from said outlet means, and a pair of tailpipesections coNnected to and receiving all gas from said single tailpipesection, the combined cross sectional area of the pair of sections beinggreater than the cross sectional area of the single tailpipe section,and means for substantially equalizing flow in the pair of tailpipesections, said means comprising a reduced diameter cross section in oneof the pair of tailpipe sections acting as a flow restricting orifice.2. An exhaust system for internal combustion engines comprising a singlemuffler having outlet means, a single tailpipe section connected to andreceiving all gas from said outlet means, and a pair of tailpipesections connected to and receiving all gas from said single tailpipesection, the combined cross sectional area of the pair of sections beinggreater than the cross sectional area of the single tailpipe section,and means for substantially equalizing flow in the pair of tailpipesections, one of said pair of tailpipe sections being larger in crosssection than the other and the difference in cross section between twosections comprising said means.
 3. A dual type exhaust system for aninternal combustion engine having two exhaust manifolds comprising apair of exhaust pipes connected one to each of said manifolds, a singlemuffler, means connecting both exhaust pipes to said muffler, saidmuffler having a single outlet, a single tailpipe section connected toand receiving all gas from said outlet, a pair of tailpipe sectionsconnected to and receiving all gas from said single tailpipe section,the combined cross sectional area of the pair of sections being greaterthan the cross sectional area of the single tailpipe section and theflow through the respective sections of said pair being substantiallyequal, said muffler having a single inlet and said means comprising acommon exhaust pipe connected to and receiving gas from both saidexhaust pipes and connected to said single inlet.
 4. In an exhaustsystem for an internal combustion engine, a single muffler having inletmeans and outlet means, exhaust pipe means connecting the engine to theinlet means, tailpipe means connected to and receiving all gas from saidoutlet means, said tailpipe means including a pair of tailpipe sectionsconnected to and receiving all gas from said muffler, and means forsubstantially equalizing flow in the pair of tailpipe sections, saidoutlet means comprising two separate outlets connected respectively tosaid tailpipe sections, at least one of said tailpipe sections includingflow restricting means to serve as said flow equalizing means.
 5. Anexhaust system for internal combustion engines comprising a singlemuffler having outlet means, a single tailpipe section connected to andreceiving all gas from said outlet means, and a pair of tailpipesections connected to and receiving all gas from said single tailpipesection, the combined cross sectional area of the pair of sections beinggreater than the cross sectional area of the single tailpipe section,one of said tailpipe sections being substantially longer than the other,and means for substantially equalizing flow in the pair of tailpipesections.
 6. A dual type exhaust system for an internal combustionengine having two exhaust manifolds comprising a pair of exhaust pipesconnected one to each of said manifolds, a single muffler, meansconnecting both exhaust pipes to said muffler, said muffler having asingle outlet, a single tailpipe section connected to and receiving allgas from said outlet, a pair of tailpipe sections connected to andreceiving all gas from said single tailpipe section, one of said pair oftailpipe sections being substantially longer than the other, thecombined cross sectional area of said pair of tailpipe sections beinggreater than the cross sectional area of the single tailpipe section,and flow restriction means in one of the tailpipe sections whereby theflow through the respective sections of said pair are substantiallyequal.
 7. A dual type exhaust system comprising a single rectanGularmuffler having a single tubular inlet at one end and a single tubularoutlet at the other end, a single exhaust pipe connected to said inletand a single tailpipe connected to said outlet, a pair of exhaust pipesconnected in a Y joint to said single exhaust pipe, and a pair oftailpipes connected in a Y joint to said single tailpipe, the combinedareas of said pair of tailpipes being larger than the area of saidsingle tailpipe.
 8. In an exhaust system for an internal combustionengine, a single muffler having inlet means and outlet means, exhaustpipe means connecting the engine to the inlet means, tailpipe meansconnected to and receiving all gas from said outlet means, said tailpipemeans including a pair of tailpipe sections connected to and receivingall gas from said muffler, and restriction means in one of the tailpipesections for substantially equalizing flow in the pair of tailpipesections.